1. Field of the Invention
The present invention generally relates to improvements in livestock trailers having vertically adjustable decks and more specifically includes a lock and release mechanism for the vertically adjustable decks which enables an operator to automatically lock vertically adjustable decks in their vertically elevated position and to effectively release the locking mechanism, all from a position on the ground exteriorly of the trailer.
2. Description of the Prior Art
Livestock trailers with multiple, vertically spaced decks are well known when it is desired to transport livestock having a relatively short vertical height. The decks are normally fixed permanently in position which requires elongated ramps to move the livestock onto the elevated decks. Alternatively, the decks are vertically adjustable and oriented at trailer floor level when loaded and moved to and locked in an elevated transport position. More specifically in movable deck trailers, the livestock or other cargo is placed on an uppermost deck at trailer floor level. The loaded deck is then elevated to a transport position and is locked in place by manually inserting locking pins, bolts or the like. The next highest vertically adjustable deck is then loaded with livestock or other cargo and elevated and locked in place. This procedure is repeated for each movable deck until the trailer is fully loaded.
Usually, each trailer deck is supported at a plurality of longitudinally spaced points along each side of the trailer by removably inserting locking pins or bolts which requires an operator to obtain access to the vertically elevated points for manually manipulating the locking pins or bolts. Vertical access to the locking pins is usually accomplished by an operator climbing onto the side walls of the trailer at a plurality of locations to accomplish secure locking of the trailer decks in their transport position and subsequently releasing the trailer decks when unloading livestock or cargo in order for the trailer decks to be lowered. The locking and releasing operation is quite time consuming and subjects the operator to the possibility of injury when manually manipulating the locking pins or bolts and when climbing the side wall of the trailer. The danger of injury with these prior art systems is especially evident when considering that the loading and unloading of livestock is usually done outdoors in areas having supporting surfaces with various materials which can become attached to the shoes of an operator which introduces the possibility of injury to the operator especially during inclement weather.
The following patents relate generally to this field of endeavor:
______________________________________ 375,764 1,774,140 3,405,661 384,913 2,099,774 3,633,963 777,732 2,129,438 3,774,577 1,558,224 2,529,893 3,812,822 1,591,033 2,970,861 3,940,174 ______________________________________
The prior art requires the operator to manually place pins or bolts through the side wall of the trailer at each deck position while climbing up the side wall of the trailer to lock the adjustable decks into place and subsequentially release them which subjects the operator to the risk of slipping or falling from the trailer side.